Related papers: Gravitational Waves from the Big Bang

Detecting gravitational waves above 100 kHz would constitute a major discovery, as any observable signal would have to arise from new physics within the late universe. Although many technologies have been identified to explore this…

As a space-borne gravitational wave observatory, TianQin can observe a large variety of gravitational wave sources. The rich signals can be composed by different types of astronomical systems, like Galactic compact binaries, inspiral of…

The imprint of gravitational waves (GWs) on large-scale structures (LSS) is a useful and promising way to detect or to constrain them. Tensor fossils have been largely studied in the literature as an indirect way to detect primordial GWs.…

Primordial gravitational waves are amplified during eras when their wavelengths are pushed outside the cosmological horizon. This occurs in both inflationary and ``pre-big-bang'' or ``bounce'' cosmologies. The spectrum is expressed as a…

Inflationary cosmology is successful in explaining a number of outstanding cosmological issues including the flatness, the horizon and the relic issues. More spectacular is the experimental confirmation of the structure as arose from the…

The theory of inflation provides an elegant explanation for the nearly flat universe observed today, which represents one of the pillars of the standard cosmological model. However, recent studies have reported some deviations from a flat…

Gravitational waves are propagating undulations in the spacetime fabric, which interact very weakly with their environment. In cosmology, gravitational-wave distortions are produced by most of the inflationary scenarios and their…

Primordial gravitational waves from the very early stages of the universe, such as inflation or bounce processes, are an irreducible cosmological source of the stochastic gravitational wave background (SGWB). The recent detection of SGWB…

Near comoving wavenumber k, the gravitational-wave background (GWB) from inflation carries information about the physical conditions near two moments in cosmic history: the moment when k ``left the horizon'' during inflation, and the moment…

Gravitational Wave Astronomy is becoming a reality as Earth-based interferometric gravitational-wave detectors reach the design sensitivities and move towards advanced configurations that may lead to gravitational-wave detections in the…

Primordial gravitational waves generated during inflation lead to the B-mode polarization in the cosmic microwave background and a stochastic gravitational wave background in the Universe. We will explore the current constraint on the tilt…

Gravitational waves are ripples in spacetime generated by the acceleration of astrophysical objects. A direct consequence of general relativity, they were first directly observed in 2015 by the twin Laser Interferometer Gravitational-Wave…

Gravitational wave astronomy opened dramatically in September 2015 with the LIGO discovery of a distant and massive binary black hole coalescence. The more recent discovery of a binary neutron star merger, followed by a gamma ray burst and…

These lectures discuss how the direct detection of gravitational waves can be used to probe the very early Universe. We review the main cosmological mechanisms which could have produced relic gravitational waves, and compare theoretical…

This paper is the third in a series of theorems which state how cosmological observations can provide evidence for an early phase of acceleration in the universe. Previous theorems demonstrated that the observed power spectrum for scalar…

We study the primordial gravitational wave background produced in models of single field inflation. Using the inflationary flow approach, we investigate the amplitude of gravitational wave spectrum in the frequency range 1 mHz - 1 Hz…

The LIGO-VIRGO collaboration has detected directly on Earth the gravitational wave signals generated by the collision and the merger of two massive black holes at astronomical distance. This major discovery opens up the way to Gravitational…

In gravitational-wave detection, special emphasis is put onto searches that focus on cosmic events detected by other types of astrophysical observatories. The astrophysical triggers, e.g. from gamma-ray and X-ray satellites, optical…

Gravitational-wave astronomy has revolutionized humanity's view of the universe, a revolution driven by observations that no other field can make. This white paper describes an observatory that builds on decades of investment by the…

Many motivated extensions of the Standard Model predict the existence of cosmic strings. Gravitational waves originating from the dynamics of the resulting cosmic string network have the ability to probe many otherwise inaccessible…